Optical Properties of the Narrow-Band Ferroelectrics: First Principle Calculations

control of the optical properties of nanoparticles by laser fields

در این پایان نامه، درهمتنیدگی بین یک سیستم نقطه کوانتومی دوگانه(مولکول نقطه کوانتومی) و میدان مورد مطالعه قرار گرفته است. از آنتروپی ون نیومن به عنوان ابزاری برای بررسی درهمتنیدگی بین اتم و میدان استفاده شده و تاثیر پارامترهای مختلف، نظیر تونل زنی(که توسط تغییر ولتاژ ایجاد می شود)، شدت میدان و نسبت دو گسیل خودبخودی بر رفتار درجه درهمتنیدگی سیستم بررسی شده اشت.با تغییر هر یک از این پارامترها، در...

First–Principle Calculation of the Electronic and Optical Properties of Nanolayered ZnO Polymorphs by PBE and mBJ Density Functionals

 First principle calculations of nanolayered ZnO polymorphs (Wurzite–, Zincblende–, Rocksalt–structures) in the scheme of density functional theory were performedwith the help of full potential linear augmented plane wave (FP-LAPW) method. Theexchange - correlation potential is described by generalized gradient approximation asproposed by Perdew–Burke–Ernzrhof (GGA–PBE) and modified Becke–Johns...

Ferroelectrics at the Nanoscale: A First Principle Approach

The field of ferroelectric materials is driven by its possible use in various micro-electronic devices that take advantage of their multifunctional properties. The existence of a switchable spontaneous polarization (see Figure 1) is at the basis of the design of non volatile ferroelectric random access memories (FERAMs), where one bit of information can be stored by assigning one value of the B...

Optical Properties of Ferroelectrics and Measurement Procedures

Structural, electronic, and optical properties of NiAl3: First-principles calculations

We report ab initio density-functional calculations of the structural, electronic, and optical properties of NiAl3, using the full-potential linearized augmented plane wave method within the generalized gradient approximation to the exchange-correlation potential. The D011 structure is found to be energetically favorable over both the cubic L12 and A15 phases. The density of states around the F...